Bore safety device for fuses



oct. 3o, 192s.v 1,689,470

A. ADELMANI BORE SAFETY DEVICE FOR FUSES y Filed Feb- 20, 1925 2 Sheets-Sheet 1 atboznu l Patented ct. 30,

UNITED-STATES ABTHIUB ADELMAN, OF CHESANIiNG, MICHIGAN.

E'oEE SAFETY DEVICE Eon EUsEs.

(GRANTED UNDER THE or or manen a, 1883, .is AMENDED Aran. so, 1925;'370 o. o. 75?.)'1

The invention described 'herein 'may be manufactured and used `by or for the Government forl governmental purposes without the payment t'o me of any royalty thereon.

The subject of .this invention is a bore safety device for fuses. v

This invention relates particularly to bore safety devices in which a member slidable transversely of the fuse body is released to armed position during the rotational flight of a projectile. Considerable diii'iculty has been encountered in devices of this type in that the safety pinsI which retain the slidable member. in unarmed position are not disengaged therefrom until full rotation of the projectile is attained,'at which time, the slidable member is'tending to arm therebyintroducing a bind- A practical embodiment of the invention is ing action between the parts.

To eliminate this binding action, I provide a 4safety pin,- several types being shown,v in which lthe force of setback on acceleration may initiate the withdrawal of the pin to 1noperative' position so that arming may be completed,duringrotatiom or, set back may :completely cause withdrawal of the pin which lis then maintained in this position by centrifugal ,force due' to rotation of the projectile.

The safety pin has its center of gravity so placedthat rotatioir'alne tends to-lock itmore firmly but on setback the center of gravity of the pin is shifted to thelopposite side of the axis of the projectile to permit withdrawal of the pin to inoperative position. A

Another important object of this invention is to interlock the-'slidable member and the plunger, theI plunger being released as the slidable member'is moved to amed position. This eliminates the. necessity of providinv'a centrifugal pin or other arming device or the plunger and also eliminates the diiiculty which has been encountered due to the pins returning to locking position during flight.

To prevent the slidable memben from arming while in the bore of the gun, it isl placed at an angle to the fuse body although the same result may be accomplished by providing an auxiliary safety pin when it is desired to dispose the slidable member perpendicular to the axis of the projectile.

lTo these and other ends, the invention consists inthe construction, arrangement, and combination of elements',f'described hereinafter and pointed out inthe claims forming a part of this specification.

illustrated in the accompanying drawings, in which, i

Pmi-.NT emes;

.Fig 1V is a longitudinal sectional view 0f a fuse'constructed in accordance with the in vention Fig. 2 is 'an inclined transverse sectional View taken on a plane containing the longi- `tudinal aie's of the bolt and safety pin and showing theni' in unarmed position;

Fig. 3 1s a similar view boltin armed position; ,e

Fig. 4 is a fragmentary longitudinal secshowingthe pin and tional View taken at right angles to Fig. l and showinga modied form armed position;

of Fig. 4;

Fig. 6 is a similar view of a modifica-tion of the safety pins shown in Fig. 5; v

Fig. 7 is a plan view of the'bolt; Fig. 8 1 s a side elevation of the Fig. 9 is a plan view thereof.

of safety pin in the I f i f 70 f Fig. 5 is a similar view of a modification 1 plunger; and

Referring to the drawings by numerals of I i reference My improved safety device is shown as apf plied to a combination fuse in which afuse head 10 is threadedly connected to a fuse body ably mounted a striker 131p-rovided lintermediate its ends with a screwsthreadedsportion 14. which threads into an aperture 15 in the caslng `to retain the striker in inoperative position, if desired.l The striker may be releasably held in its forward position by means of a coiled spring 16. i

The fuse is formed with a cavity 17 between the head and the body and into this cavity projects a`.xed firing pin 18carried by the fuse head. Within the cavityis a plunger 19 which is formed with a central aperture 20 through which the striker is adapted to pass and a second aperture 21, off center, for the reception of a priming cap 22, and a powder 'column 23. The offset aperture is in commu- The foregoing elements are but briefly described as they invention.

The plunger is formed with a circumferform nopart of the lpresent .clination the bolt isprevented from arming while in the bore of the gun. The bolt is auxiliarly'held in unarmed position against the plunger and a shoulder 30 of the passage by a spring 31 confined between the bolt and the plate 32 which closes the passage. The opposite end of the bolt formed with an aperture 33 passing entirely therethrough in which is frictionally retained a cup 34 carrying a detonating element 35.

When in armed position the detonator is aligned with apertures 36 and 37 in the fuse body, respectively 'above and below the passage, the upper aperture adapted to permit passage of the striker or the fiash from the primer accordingly as the fuse is set for instantaneous or delay action, and the lower aperture being in communication with a booster chamber 38 which is adapted to receive a metal cup 39 for spacing a booster charge 40from the bolt.

The bolt is primarily maintained in unarmed position by a locking device which may assume different forms as shown in Figures 2 to 6. In each instance the locking device consists of a pin either carried by the fuse body or the bolt and whose center ofV gravity is so placed that rotation of the pro'ectile will only tend to lock it more firmly w ile it can only,be moved to release the bolt through the force-of setback on acceleration or through,

this force, plus centrifugal force during rot-ational flightI of the projectile.

As 4seen ,in Figures 2 and 3, the bolt is formed with an approximately centrally disposed slot 4l which is normally in register with the short slot 42 on one side and a long slot, 43 on the other, both of these s lots being in the fuse body. The slots are inclined with respect to tlelongitudinal axis of the fuse so that on set back, a pin 44 normally disposed in slots 41 and 42 will be moved into the slot 43, the center of gravity of the pin shifting to the opposite sides of the axis of the projectile. Entire withdrawal of the pin from the bolt is completed by centrifugal force during the rotational flight of the projectile.

The slot 43 is closed by a plug 45 against which a spring 46 acts to normally hold the pin in locking engagement with the bolt.

In the modified form shown in Figure 4, the pin 44 is of less length than the diameter of the bolt and is normally projected into a slot 47 in the fuse body by its spring which center of gravity is shifted and will be maintained in this position within the bolt through centrifugal force.

Referring to Figure 5, an auxiliary pin 49 is provided to cooperate with the pin 44 shown in Figure 4, and to lock the bolt until acceleration ceases at which time the auxiliary pin is entirely returned to the slot in the fuse body through centrifugal force. A4 light springl may be used to assist in this return'if desired. This construction would enable the bolt to be disposed perpendicular to the longitudinal axis of the fuse instead of at an incline and furthermore, any jolt tendin to arm the pin 44 would at the same time jar t e auxiliary pin to locking position.

In Figure 6, I have shown both the pin 44 and its hollow auxiliary pin 50 as carriedv within the bolt, the pins projecting at opposite sides of the bolt` into slots formed in the fuse body. On setback the pin 44 will be withdrawn into the bolt while the auxiliary lll) pin 50 will ten-d to remain in locking engagement with the fuse body. .The center of gravity of the pin 44 will be shifted to ithe right while the center of gravity off the auxiliary pin 50 and-also that of the combined pins will still remain to the left.` Through centrifugal force, the pin 44V'Will be held against the closed end ofthe auxiliary pin while the auxiliary pin and with it the pi11'44 moves to the left to be disengaged from its slot in the fuse body until its movement is limited by the wall of the passage 27.

To prevent rotational movement of the bolt as it moves laterally and also to insure retention of thebolt in the armed position, I projvide a. U-shaped wire 51 loosely disposed in a 'similarly shaped groove 52 on the bolt, the

wire abutting a shoulder 53 in the passage and held thereagainst by centrifugal force when the bolt moves to the right., When the bolt has arrived in the armed position the wire 51 will have sufficient clearance to permit its displacement with respect to at least one element of the groove (Fig. 3) thus preventing the bolt from returning to unarmed position.

While in the foregoing there has been illustrated and described such combination and arrangement of elements as constitute the preferred embodiment of the invention, it is nevertheless desired to emphasize the fact that interpretation of the invention should only be conclusive when made in the light of the subjoined claims.

I claim:

1. A fuse including a fuse body, said body formed with a cavity and a transversely inclined passage, a plunger movably mounted within the cavity, said plunger formed with l a circumferential groove, a bolt slidably mounted 1n the passage, a hooked extension on said bolt for engaging the groove of the plunger, a firing element carried by the bolt, and a centrifugally moving locking member Whose center of gravity is shifted on set back, to permit functioning to release the bolt.v

2. A fuse including a fuse body, said body formed with a cavity and a transversely inclined passage, a plunger movably mounted Within the cavity, said plunger formed with a circumferential groove, a bolt slidably mounted in the passage, a hooked extension on said bolt for engaging the groove of the plunger, a firing element carried by the bolt, and means for releaseably holding the bolt and plunger in unarmed osition.

3. A fuse including a use body, a plunger movable longitudinally of the bod a bolt slidable transversely -of the body, a ring element carried by the bolt, and means formed on the bolt \for vlocking the plunger in unarmed position.

4. A fuse including `a body, said body formed with an inclined transverse passage, a bolt slidably mounted in the passage, a firing element carried by the bolt, a locking pin normally extending through the bolt on a plane perpendicular to its longitudinal axis and inclined With respect to its horizontal axis, said body formed with slots in register With the pin, means for normally disposing the center of gravity of the pin on one side of the axis of the fuse, and said pin adapted on setback to move radially of the fuse to be (isengaged from the bolt through centrifugal orce.

5. AI fuse including a body, said body formed With an inclined transverse passage, a bolt slidably mounted in the passage, a firing element carried by the bolt,I a locking pin carried by the bolt in a plane perpendicular to its longitudinal axis. and inclined with respect to its horizontal axis, said bodyformed with a slot in register with the pin, means wfor normally projecting the pin in said slot, and said pin adapted on setback to have its center of gravity shifted to the opposite side of the axis of the fuse.

6. A fuse including a body, said body formed with a transverse passage, a bolt slidably mounted in .the passage, a firing element carried by the bolt, a plurality of lockring pins carried by the bolt, and normally projecting into the body on either side of the bolt, one of said pins adapted to be With'- drawn into the bolt on setback, and the other of said pins adapted to be Withdrawn into the bolt through centrifugal force, and each of said pins being also ada ted to be maintained by centrifugal force 1n opposite sides ofthe bolt.

7. A fuse including a body, said bod formed with a transverse passage, a bolt sli on set-back and the other of said'membersbeing movable by centrifugal force from position of rest to ultimately release thebolt to armed position'.

9. A fuse including a body, said body... formed With a transverse passage, a bolt slidably mounted in thepassage, a tiring element carried by the bolt, anda centrifugally held U-shaped Wire Working in a guide in the bolt for preventing rotational'movement of the bolt as it moves laterally in the passage, said Wire adapted to be clear of the boltwhen armed and susceptible of displacement with respect to its guide whereby to prevent return of the bolt.

10. A fuse including a body, said body formed With a transverse passage, a boltl slidably mounted in the passage, a liring element carried by the bolt, and a centrifugally held U-shaped Wire Working in a uide in the bolt., saidwire adapted to be clear ofthe bolt when armed and susceptible of displacementwith respect to its guide whereby to prevent return of thebolt. I

11. A fuse including a body, said body formed with a transverse passage, a bolt slidably mounted in .the passage, a firing element carried by the bolt, and a centrifuoally held U-shaped WireA working in a gui e in the bolt for preventingv rotatlonal movement of the bolt as it-moves laterally in the passage.

12. A fuse including a body, a member movable longitudinally of the body andv a `member movable transversel of the body and throughout its movement lntersecting the axis of the longitudinal men1ber,: said transverse member adapted to releasably hold the longitudinal member against movement.

13. A fuseincluding a body, a b olt slidable transversely therein, a pair of telesco ing locking members for locking the bolt 1n unarmed position, one of said members being movable on set-back while the other remains stationary and both of said members movable as a unit under the'influence of centrifugal force to ultimately release-the bolt to armed'position. v

- ARTHUR ADELMAN 

